Blown head gasket?

Discussion in 'Engine Topic' started by wiseryder, May 6, 2019.

  1. wiseryder

    wiseryder Veteran Member Lifetime Gold Member

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    Hi all, I have a 350 engine in my boat, I discovered yesterday that there is milky oil in the pcv hoses. runs fine.
    Is it the head gasket ??
    thanks
     
  2. RS1979

    RS1979 Veteran Member Lifetime Gold Member

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    If the head gasket is blown, you will either have water in the oil or white smoke coming out of the exhaust. Since it's running fine, I doubt that's the problem. To eliminate the blown head gasket do a bleed down test on it. It could be condensation from winter storage.
     
  3. wiseryder

    wiseryder Veteran Member Lifetime Gold Member

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    Well, there is white smoke out the exhaust( it got thru-hull ) but I've seen that lotsa times on other boats.
    I will pull the dipstick out and have a look.
    The one side of pcv hose is almost clogged with the stuff, the other side just a little bit of it
    Im not sure I know what a bleed down test is, unless it's called something else?
     
  4. RS1979

    RS1979 Veteran Member Lifetime Gold Member

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    Sorry I meant a leak down test
     
  5. wiseryder

    wiseryder Veteran Member Lifetime Gold Member

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    Dipstick is clean, all the white junk was on the underside of valve covers, I wiped it clean.
    Checked all the plugs, they all look the same and look good.
    I will change the oil and see what happens
    Thanks RS
     
  6. krabben1

    krabben1 Veteran Member Lifetime Gold Member

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    Thats condensation.If the breathers are old,and the pcv dont rattle when you shake,itd be good to get new ones.
     
  7. krabben1

    krabben1 Veteran Member Lifetime Gold Member

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    Not saying that was the cause,but theyre prolly gooed up as well.
     
  8. wiseryder

    wiseryder Veteran Member Lifetime Gold Member

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    This engine don't have actual pcv vavles, just the hoses to covers with a fitting without the ball.
    I checked into it, was told marine engines don't use them.
    Hoses go straight to flame arrester
    If someone here know's different, I'm all ears
    I'm going to dealer tmrw for a new T-stat,I will ask them
    Thanks guys
     
  9. jeff swisher

    jeff swisher Veteran Member

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    Cold running boat engines and car engines will milk up the under side of the valve covers this is much more of an issue in winter time conditions.
    Do you have a temp gauge on the boat?
    I found no condensation at 130 degrees in out boats.
    But those were ran for quite some time 1 hour or more.. not ran for 5 minutes then shut off.

    If you install a big cam or should I say cam with a lot of overlap you can move the water port from exhaust manifold to a farther away area like the rubber coupler at the far back of the boat right before it goes through the hull.

    Did this on a 355" inboard with ported 993 heads and Comp Thumper cam.
    We ran it with dog house off though.
    It was sucking water through the overlap period and moving the water back fixed it.. Yes oil got milky until we fixed that.

    I had a 1982 Ford with 376,000 miles on the 200" inline 6.
    I could not get enough heat in that engine even with a small single core radiator blocked off all the way.
    That thing in winter would make a lot of condensation in the valve covers.
    I could shake water drops off the dipstick and out of the breather cap.

    Summer time never an issue.

    Could be a thermostat like you know.
    Do you know your running temp?
     
  10. wiseryder

    wiseryder Veteran Member Lifetime Gold Member

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    Jeff, funny you mention temp's, I bought this thing over the winter, very nice 230 Powerplay, got it cheap imo.
    yesterday when I discovered this, Has it on the water for 2 hours ,temps were fine anything over 1200 rpm;s , idle around in gear, within 2-300 yards , temps rose like to almost 200, Raise the rpm a tad , they drop like a rock..
    Got the stat out ( in pieces ) , grab a new one tmrw
    Dang boats, money pits, 3rd boat I've owned.
    So, your saying these cold running engines do this ?
    I don't run it for 5 min's when it's on the water, it's awhile
    Or gotta build more heat ?
    Thanks
     

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